Furnace



H. F. SMITH.

FURNACE.

APPLICATION FILED mac. 4. 1911.

gg Patented May 23, 1922.

3 SHEETSSHEET 1 WWW H. F. SMITH,

FURNACE.

' APPLICATION HLED DEC. 4, 1917. L%1] 9@ I Patented May 23, 11922..v

3 SHEET8-SHEET Z,

NTER H. F. SMITH.

FURNACE.

APPLICATION FILED DEC.4,1917.

gg Patented. May 23, 1922.

3 SHEETSSHEET 3.

$7M? gm [0%, W HAW/MM) r 1: it. an, or Lmrne'ron, onto; assrerron, BYmnsnn assreivrrnnrs, TO

THE GAS EAR-CH COMPANY, OF DAYTON, 0M0, A CORPORATION OF OHIO.

FURNACE.

Specification of Letters Patent. Patngnt edl .lway 23, 1922.,

Application filed Decemhert, 1917. I Serial No. 205,383.

To all whom it may concern Be it' known that I, HARRY- F. SMITH, acitizen of the United States of America, residing at Lexington, Richlandcounty Ohio,

haveinvented certain new and useful Improvements in Furnaces, of whichthe fol= lowing is a full, clear, and exact-description.

Thls invention relates to furnaces and more particularly to regenerativefurnaces of the type-adapted to utilize fuel in the form of gas orvapor.

One object of the invention is to provide a regenerative furnace whichis extremely simple in form and therefore quite easy of construction,and in which the complicated reversing mechanism in ordinary useissupplanted by mechanism which is not only easy' and inexpensive ofinstallation, but which is also adapted to cause a minimum of troubleduring its operation and maintenance. 7

Other objects and advantages will be apparent from the description setout. below,

.when taken in connection with the drawing.

The principal objection to the regenera tive' furnaces now in use arisesfrom the complexity of the reversing valves, and the operating mechanismco-operating therewith, and from the great expense necessarily involvedin installing such furnaces. In carrying my invention into effect, I soconstruct the furnaces that the furnace structure is itself simplifiedand by such simplification the necessity for valve mechanism forcontrolling the flow through the regenerators andstacks entirelyobviated. For securing this result I pass the fuel, 'gasor vapor, underpressure, into the working chamber through elongated passages whichconnect the regenerators to opposite ends of the working chamber. Thearrangementof the passages and nozzles is such that they constitute ineffect injectors, the flow of fuel along a passage way inducing acorresponding flow of air from the co-operatmg regenerator to theworklng chamber,

wherein the mixture is burned. The regen erators have at all timesunobstructed com-- munication with the air and, as aresult of.

the flow of gas and of air, from one of the regenerators, across theworkin being unimpeded, the heate prodnets of combustlon pass freelyupwardly throu h the other regenerator imparting heat t ereto. In afurnace of this type rechamversal of the flow therethrough is broughtabout by directing the supply of fuel from one nozzle to the. other.ture thereversing valves for controlling the regenerative chambers,aiong with the operating gear therefor, are entirely dispensed with, theonly reversing valve used being a single three-way valve, of any desiredtype, for use in the gas line to control the point of application of thegas to the working chamber.

I have illustrated in the accompanying drawing a preferred embodiment ofa regenerative furnace comprising my invention. In the drawing, in whichlike characters of reference designate like parts throughout the severalviews thereof:

Fig. l is a sectional view through the furnace along the line 1-1 ofFig. 2;

I Fig. 2 is a side elevation of the furnace;

Fig. 3 is'a rear elevation of the furnace showingthe reversing valve andone form In such a struc of mechanism for automatically operating In thedrawing the numeral 1 designates generally a furnace resting upon afounder-- tion 2 of any desired construction and having co-operatingtherewith a stack or ventilator 3. This stack is not positively con--nected to the furnace in any way, butin reality is nothing more than aventilator or waste gas conveyor adapted to carry off, to the atmosphereoutside the building housing the furnace, the waste gases constitutingthe products resulting from the combustion in the furnace.

Near the base of the-furnace is a working chamber 4 in which the fuel isburned, and in which any material to be treated is placed. Located abovethis working chamher are two regenerators 5 filled with checker brickwork. Leading from the lower end of each regenerator 5 to the adjacentend of 'the'working chamber 4, is a' connecting passageway 6. Thepassageways Gas shown are inclined and any gases passing down one ofthem will sweep across the working chamber 4 and out through the other.In the top of each regenerator is a port 7 so located that gases passingupwardly therethrough will be caught by the stack3 and vented to theatmosphere. The

orts 7 are unobstructed so that each re en P a:

erator is at all times in free communication with the atmosphere. It isthe usual practice to provide reversing valves for controlling theseports, but in my improved furnace flow through one regenerator intotheworking chamber and thence upwardly through the other regenerator isinduced by the flow of fuel. Consequently reversing valves forcontrolling the port 7 are unnecessary, the only valve needed being onefor directing the flow of gas to each passageway 6. And any desired formof the three-way valve may be used for this purpose. I have shown theregenerators as located above the working chamber, but it is obviousthat they might be just as advantageously located below. Where theregenerators are located above the working chamber, the naturaldraftthrough the apparatus will be a material factor in carrying theproducts of combustion upwardly there-' through, but where theregenerators are 10- cated entirely below the working chamber thepressure at which the fuel is fed must be sufficient to maintain acontinuous circulation through the apparatus.

Passing through the walls of the furnace adjacent the point where eachpassageway 6 opens into the regenerator 5 co-operating therewith are gassupply nozzles 8. The number of passageways 6 connecting eachregenerator to the corresponding end of the working chamber coincideswith the number of gas nozzles used, a separate passageway beingordinarily used for each nozzle. Of course the number of nozzles to eachpassageway may be varied if particular circumstances demand. It isobvious that these nozzles arejust as well adapted for supplying liquidfuel, such as oil, in the form of spray and the invention is thereforenot limited to a regenerative furnace adapted to use gas as a fuel, thefurnace disclosed being capable of operating satisfactorily upon avariety of fuels. These nozzles are so arranged that any gas forcedtherethrough will flow axially or longitudinally of the passages 6across the opening from the regenerators into said passages, thepassages 6 and nozzles 8 constituting in effect injectors adapted,upon-passage through'either of the nozzles of gas under pressure, towithdraw air from the regenerator adjacent such nozzle and force themixture of air and gas across the working chamber 4 from whence theproducts of combustion will pass up through the other passageway andregenerator and out through the port 7 thereof. It is evident that whengas is forced through .there. It is also evident that if gas underpressure continues to flow in through one of the nozzles 8 and thepassage 6 co-operating therewith, the heated gas resulting from theburning in the chamber 4 of such gas will pass upwardly through theother passage (3 into the regenerator 5 co-operating therewith, givingup heat to the checker brick therein as it passes on its way to the port7 and stack 3. If now the direction of flow of the gas is reversed, i.e., if the gas is directed into the passage 6 through the other nozzle8, while the flow of gas through the first nozzle, and consequentlythrough the first passage, is at the same time cut off, the direction offlow through the entire furnace will be automatically reversed. Undersuch conditions a flow of air will be induced through the otherregenerator, which has been heated to a high temperature by the passagetherethrough of the heated products of combustion, and because of theinitial heat imparted to such air during its passage through theregenerator, the temperature in the working chamber at will be greatlyincreased. In order that the passages 6 and nozzles 8 shall give rise toan injector action, the longitudinal dimension of such passages must begreater than their transverse dimension, the greater the preponderanceof length over breadth, within reasonable limits, the greater theinjector action produced.

Because of their location the nozzles 8 are subjected to an extremelyhigh temperature and thus tend to burn out very rapidly. To overcomethis defect these nozzles are made of some metal, such as aluminum,which is a very good conductor of heat, and the outer ends thereof,which are exposed to the atmosphere, are provided with a series ofradiating ribs or fins 9. These ribs or fins increase the radiatingsurface of that part of the nozzle exposed to the atmosphere, and, sincethe metal of which the nozzles are constructed is a very good conductorof heat. tend to'withdraw heat from the inner end thereof and radiate itto the atmosphere so rapidly that the temperature of the inner end ofthe nozzles is kept down and the tendency to burn them out thuslessened. Threaded into the outer end of each nozzle is a plug 10adapted to carrytherethrough a threaded stem 11 the inner end of whichco-operates with the opening 12 in the nozzle 8 to vary the effectivearea of that opening,

-upon movement of the stem 11 axially of thenozzle. lBy Varying theeffective opening of the nozzles without any variation in the pressureof the gas supplied thereto, the velocity of the flow of gas may bevaried. Since the inductive action on the air in the regenerators isdependent upon the velocity of the flow in the passages 6, theproportion of air to gas, in other words the composition of thecombustible mixture fed to the working chamber, can thus be varied atwill. And of course the amount of gas or vapor which can flow throughthe nozzles may be thus also varied. As shown in Fig. 2 1 prefer to usetwo gas supplying nozzles for each end of the working chamber 6, but itis obvious that this number may be varied as desired to meet particularconditions which may arise. It is only necessary that the gas supplyingnozzles used have suflicient capacity to furnish the amount of gasneeded for generating the desired temperature in the working chamber 4and that the rate of flow of gas through these nozzles be sufiicient toinduce the necessary fiow of air through the regenerators.

From the above description it is quite evident that the structure of thefurnace is greatly simplified, inasmuch as the reversing valves whichordinarily control the regenerative chambers are completely dispensedwith, and it becomes merely necessary to provide a single valve forcontrolling or directing the flow of gas to either set of nozzles 8.Mechanism for automatically directing the fiOW.Of gas to either set ofnozzles is shown in Figs. 2 and 3. Leading from a source of supply ofgas under pressure is a main 13 which leads into the casing of thethree-way valve 14. Leading off from the valve 14 are two branch ipes15, each of which is, adapted to su p y gas to one of the sets ofnozzles 8. v igidly attached to some part of the apparatus adjacentvalve 14 is a motor 16 adapted to drive a train of .reducing gears 17,18 and 19. Attached to the gear 19 is a crank 20, the free end of whichis operatively connected to one end of the rod 21 which has its otherend in turn connected to the valve operating handle 22..

- driven by a clock or similar means and adapted at predeterminedintervals to cause the passage of a current therethrough to bring aboutactuation of said motor and so of the valve. And it is obvious that byproperly proportioning the gears 17, 18 and 19, and the timing mechanism23, the movement of the valve 14 will be just sufficient to cut ofi'-the flow of gas through one of the pipes 15, and permit of the flowthereof felt through the other pipe 15. The valve shown generally at 14is similar in structure to the valve described in my Patent No. 863,004,dated Aug. 13, 1907, but any other type of three-way valve desired maybeused in place thereof, the changes in the actuating mechanism madenecessary by such substitution bein si'mple mechanical within theability of any skilled mechanic.

By .making use of the valve actuating mechanism described above, theoperation of this improved type of furnace can be made entirelyautomatic. And by properly connecting the valve actuating mechanism of aplurality of furnaces such as described, it is evident that a largenumber of such furnaces may be controlled from one central timingmechanism, so that the individual furnaces will be reversed in anydesired order. Where such a plurality of furnaces are used, amaster'timing mechanism for bringing aboutsuccessive reversals of thevarious furnaces is necessary. Otherwise it is conceivable that the flowof gas through all of The operation of such a furnace is not dependentupon the precise form of valve actuating mechanism disclosed, it beingpossible to substitute various other valve controlling devices therefor.One form of valve cont-rolling device that may be substituted problems,easily 4 for the form shown in Fig. 3, is illustrated in Fig. 5. Asillustrated in that figure, 13 is a gas supply main which leads from asource of supply of gas under pressure and opens into the valve casing24. This valve, like that shown in- Fig. 3, is also similar to the valvedescribed in my Patent No. 863,004, dated Aug. 13, 1907. Opening fromthe casing 24. are two branch pipes 15 which lead to the nozzlesj8, andsupply those nozzles with gas under presssure. Operatively connected tothe valve operating handle 25 by means of a link 26 is a rod 27, theother end of which is connected to a piston '28 located in the cylinder29.

Operatively connected to the operating handle 25 by means of a link 30is a rod 31 which passes through the support 32, and is rigidly heldagainst motion in any direction other than co-axial with the rod'27. Thepiston rod 27 is also restrained from any movement other than axial.Operatively connected to the upper end of the rod 31,

by means of the link 33, is a lever 34 ful-.

from the position shown in dotted lines at 36, its leverage rapidlydecreases, and upon downward movement, its leverage rapidly increases.

Situated adjacent the cylinder 29 is a pilot valve casing 37, having twopipes 38 and 39 opening into opposite ends thereof. These pipes arebranches of a pipe 40 which leads from a source of supply of air undermoderate pressure, the pressure under normal working conditions beingabout six pounds. Located in the casing is a piston valve 41, normallyurged toward one end of the casing by means of the spring 42. Attachedto the other end of the valve 41 and extending co-axially through theend of the casing 37 is a rod 43 adapted to co-operate with thecam-bearing wheel '44, the spring 42 urging the valve 41 and rod 43longitudinally of the casing 37 to cause the rod 43 to be in continuousworking contact with the periphery of the cam wheel 44. Carried by thevalve 41 are two peripheral ports 45 and 46, the port .45 being adaptedupon proper positioning of the valve to register with the inlet pipe 39and port 46 with the inlet pipe 38, but the positioning of these portsis such'that both of them can not be connected with both inlet pipes atthe same time. I

Leading off from the casing at points substantially 180 degrees from thepoints of entrance of the pipes 38 39 are two pipes 47 and 50, whileleading from the casing intermediate the'points of entrance of the pipes38 and 39 are two exhaust pipes 4849. The pipes 4750 are so arrangedthat one of them is in connection with one of the inletpipes 3839 whilethe other is in connection with its corresponding exhaust pipe 4849. Asshown in the drawing the pipe 47 is in operative connection with thepipe 39, and the air under pressure is led from said branch pipe 39through the port 45,

and out through the pipe 47 while the pipe 50 is connected through theport 46 with its exhaust pipe 49 so that the pressure theretofore storedup in the pipe 50 and that part of the mechanism connected thereto mayex haust to the atmosphere. 7

The pipes 47-50 lead to opposite ends of a valve casing 51 having avalve 52, carrying a peripheral port 53, slidable therein. Carried bythe ends of the valve casing 51 are inwardly extended stops 54,'adaptedto main tain at all times a free space between each end of the valve andthe corres ondiong end of its casing. The pipes 47 an 50 open into thecasing 51 in such wise that any pressure fluid passing therethroughenters these free spaces between the valve and the valve casing. Openinginto the casing 51, intermediate its ends, is an inlet pipe 55 connectedto a source of supply of air under high pressure, a pressure of about100 lbs. being used in actual practice. Leading of? from the valvecasing are two pipes 56 and 57, the

former of which opens into the lower end of the cylinder 29, the latterexhausting to the atmosphere. The port 53 in the valve 52 is so arrangedthat the pipes 55 and 56 can be connected with each other and the pipes56 and 57- connected with each other. The three pipes, however, cannotbe connected to each other at the same time, nor can the pipe 55 beconnected to pipe 57.

The operation of the device is as follows: The cam wheel 44 whichcarries thereon any desired number of cams, the number being dependentupon the desired frequency of reversals, is connected to a clockmechanism adapted to rotate such wheel at a predetermined rate of speed.As illustrated this wheel carries thereon four cams 58, there beingnecessarily four depressions 59 between such cams, which arrangementwill give rise to eight reversals every revolution of the cam wheel.Ordinarily the cam wheel will be so arranged as to make one revolutionan hour, so that with the number of cams shown in the drawing, therewill be a reversal every seven and one-half minutes. As shown in thedrawing the piston 28 and weight 36 are in extreme elevated positionwith the valve 24 in such position as to direct the flow of gas from thepipe 13 through the upper pipe 15. As the cam wheel rotates from theposition shown to move the cam 58 out of contact with the rod 43, thevalve 41 will be urged by the spring 42 longitudinally of its casing,the rod 43 moving into a depression 59. Upon such movement of the valve41, the port 46 will connect the pipe 38 with the pipe 50, at the sametime cutting off the exhaust pipe 49, while the port 45 will bemovedinto such position that the pipes 39 and 47 will no longer register, butthe pipe 47 will register with its exhaust pipe 48 to exhaust to theatmosphere the air under pressure in the righthand end of'the valvecasing 51. As the air under pressure is beingexhausted from valve casing51, a supply of air under pressure is passing through the pipe 50 to theopposite end thereof. As the pressure in the lefthand end of the casingpreponderates, it will force the valve 52 longitudinally of the casingto close off connection between the pipe 55 and the pipe 56, and openconnection between the pipe 56 and its exhaust pipe 57. The pressure airstored in the cylinder 29 below the piston 28 will thus be vented to theatmosphere, and the pressure within such cylinder thereby decreased. Asthis pressure decreases the piston 28 urged by the weight 36 will tendto fall, the leverage increasing during downward movement of the weight.With the pressure in the cylinder 29 greatly decreased and the moment ofthe force exerted by the weight 36 rapidly increasing, the cylinder willbe forced down very rapidly. The valve 24 at the same time, because ofits operating mechanism being connected to the piston and levermechanism, will be rapidly shifted from one extreme position to theother to cut ofi' flow through the upper pipe 15, and permit -of flowthrough the lower pipe 15. And, of course, where one of the cams 58moves into contact with the rod 43 it will force the valve 41longitudinally of its casing, against the spring 42, to bring about areversal of the above operation and thus connect the upper pipe 15 withthe main 13 while closing off the lower pipe 15. It is obvious that thisreversing 'mechanism lends itself just as readily to the control of aplurality of furnaces as does the mechanism illustrated in Fig. 3.

In Figs. 6 and 7 is illustrated still another modified form of mechanismfor controlling the gas reversing valve. In the apparatus illustratedtherein, 13 is the gas supply main which leads into a valve casing 60,having. two branch pipes 15 leading therefrom. Mounted within the casing60 is a three-way disc valve which may be of any desired {conventionalconstruction adapted upon rotation to connect either one .or-the otherof the branch pipes 15 with the main 13. Itigidly connected .to thevalve operating stem 61 is a disc 62 having two stops 63 thereon adaptedto co-operate with a pawl 64.

This pawl is preferably held in contact with the dlsc 62 by means of aspring 65 and is adapted to normally hold the disc against rotation.Parallel to the disc 62 and adjacent thereto is a second disc 66.Rigidly attached to the disc 66 is a worm gear 67 in operative contactwith a worm pinion v carried'by theshaft 68 of the motor 69.

hill

Located between the discs 62 and. 66, and having an end thereof attachedto each, is a spring 70. The motor 69 is adapted to rotate continuouslyinhone direction, and, by

means of the worm' gearing,- to rotate in unison therewith the disc 66.Inasmuch as the disc 62 is normally held againstrotation by means of thepawl 64, rotation of the disc 66 will cause a winding up of the spring70 to increase the tension thereof. Carried by the disc 66 is a lug 71adapted during rotation of the said disc to contact with the pawl 64 tomove that pawl out of engagement with the stop 63. When the-pawl 64 isthus moved the disc 62 acting under the influence of the spring 70, willrotate and during such rotation willfactuate the valve controlling flowthrough the casing 60 to open one of the pipes 15 and close the other.And, by

I properl proportioning the various parts of the actuatlng mechanism,reversals of the valve can be secured at any desired predeterminedintervals.

From the above description it is obvious that I have invented a type offurnace in which are eliminated the objectionable features present inthe furnaces now in use, a furnace which is not only capable of veryeasy operation, but is extremely simple in constitute in effectinjectors drawing the heated air from the regenerators inproperproportion for mixture-with the fuel and forcing the resultingcombustible mixture into the working chamber. My invention, however, isnot limited to the precise structure and mechanical details describedherein, inasmuch as numerous changes could undoubtedly be made withoutin any way departing from the spirit, or the scope, of my invention. ora true definition of the invention, therefore, reference should be hadto the appended claims.

What I claim as new is:

1. In a regenerative furnace, a working chamber, air regenerators,valveless passages connecting said regenerators to the atmosphere,passages connecting said regenerators to the working chamber, nozzlesfor passing gas along said passages, and means for directing the flow ofgas through the nozzles.

2. In a regenerative furnace, a working chamber; regenerators associatedtherewith; valveless passages connecting said regenerators to theatmosphere; a passage connecting each end of the working chamber to aregenerator; nozzles opening into the passages, said nozzles andpassages constituting in effect injectors; means for suppyling fuelunder pressureto either of said nozzles; and means associated with saidnozzles and adapted, at predetermined intervals, to inoing without 5. Ina regenerative furnace, a working chamber; air regenerators in openco1nmunication withsaid chamber, each regenerator having a valvelesspassageway into the atmosphere; and a partition separating thepassageways to prevent the flow 0f fluid, in either direction, throughone of said passageways aifecting the flow of fluid through an adjacentpassageway.

In testimony whereof I aflix my signature.

HARRY F. SMITH.

